


AU

by notgregarious



Category: Haikyuu!!
Genre: Alternate Universe, Anal, Eventual Smut, F/M, Friends to Lovers, M/M
Language: English
Status: Completed
Published: 2015-03-09
Updated: 2015-03-11
Packaged: 2018-03-17 01:12:52
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 6,029
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3509645
Author URL: https://archiveofourown.org/users/notgregarious/pseuds/notgregarious
Summary: <blockquote class="userstuff">
              <p>Kuroo Tetsuroo has a problem. Every year on his birthday he switches into an alternate universe. But soon he discovers there's one constant in his life, a certain Tsukishima Kei.</p>
            </blockquote>





	1. You're a Boy

**Author's Note:**

> there's no smut in the first chapter, but it'll probably happened in the second or third. I mean, Kuroo doesn't even know he's pan yet, so I gotta ease him into it :p

Kuroo opened his eyes. The ceiling this time was white with plastic glow in the dark stars stuck across it. He rubbed his eyes as he sat up, his mouth erupting in a yawn. He felt heavy. It had been almost three days since he last slept this soundly. There was a picture on his desk. Faces he didn’t yet remember huddled together in the snow, their collective breath making clouds. He stood in the back of the group, his eyes looking down. So he had friends in this universe. Or he used to, anyway.

Standing up, he pulled off his shirt and threw it on the bed. He peeked in his closet. Some of the articles of clothing were the same, but there were a few here and there that he didn’t recognize. He got dressed quickly and then stepped outside of his room. The apartment was the same with a few minor differences, like the colour of the pictures on the walls. 

That must mean his previous self went to the same university in Tokyo. He spotted a philosophy textbook on the coffee table. Same major too, he noted. He walked down the hall to the bathroom. 

He stared at his reflection in the mirror. His eyes were dark and the bags under them seemed a lighter purple than usual, but still there all the same. His face was growing more angular over the years, as if the stress had sucked the plumpness from his cheeks. He ran a hand through his messy hair. It was longer than it had been the day before. He wondered if the hair salon he usually went to would still be at the end of the street in this universe. 

Eating was difficult. Each bite seemed to stick in his throat. It was tiresome. Everything was tiresome. The piece of toast grew cold as he brought it to his mouth less frequently. The feel of the chair underneath him was familiar yet it was a different one from the previous universe. It was the small differences that threw him off, like the furniture or the colours of his clothes. The way they seemed familiar even though he knew they weren’t the same as he was used to. He swirled the coffee in his mug but didn’t drink. 

Bigger things, like his relationships or the people themselves…those changed too. He could always sense those changes when he encountered them. Someone who was a friend in one universe would feel distant in the next. And eventually they would be forgotten. The forgetting was bad because he never knew when it happened. Only that it had. 

The remembering however, was worse than bad. It was a sensation so complexly woven with different emotions that he was sometimes reduced to tears he didn’t completely understand. 

There was a knock at the door. Kuroo walked down the hall, hoping it was someone that didn’t know him well enough to be able to tell something was different about him. A young man stood outside his door. He was taller than Kuroo, and thinner too. His blond hair was short and slightly curly and a scarf was wrapped liberally around the lower half of his face. The tips of his ears were red and his golden eyes were glaring. Kuroo realized that the guy probably saw him walk over from the kitchen window. Kuroo opened the door.

“Happy Birthday Kuroo,” The lanky blond said, inviting himself into Kuroo’s apartment. 

“Uh, thanks,” Kuroo said lamely.

“You always let a friend freeze to death when they come visit you on your birthday?”

“Course not,” Kuroo wracked his brains but he was sure he’d never seen this guy before in any of the previous universes he’d been in. Shit. 

“I’m Tsukishima Kei,” The guy supplied as if he had read Kuroo’s mind.

Wait a minute. Kuroo knew that name. The image of a tall blonde woman flashed through his mind.

“Tsukishima Kei…” Kuroo blinked.

“You’re a boy”

“Yes, I am,” Was Tsukishima’s disinterested reply as he made for the kitchen, shedding articles of winter clothing as he went. 

“Since when?” Kuroo asked, following him.

“Since birth.” 

Tsukishima rummaged through Kuroo’s cupboards and pulled out a black mug with a glow in the dark star painted on the side. He poured himself a cup of coffee.

“I see.”

“Was I a girl last time?” Tsukishima raised an eyebrow in amusement. He sat down at the kitchen table.

“Yes, yes you were,” Kuroo replied dryly.

“Huh.”

“DON’T ‘huh’ ME! WHAT THE HELL IS THIS?” Kuroo shouted, banging his hands on the kitchen table. The table rattled and Tsukishima’s coffee spilled over the side of his cup.

“Calm down,” Tsukishima said petulantly, lifting his cup and looking down at the spill in disdust, “Geez, the last you was a lot calmer about this. Why are you freaking out so bad? Unless…oh my, how naughty~”

“What?!” Kuroo snapped.

“Was I a cute girl? Don’t tell me you actually violated my poor innocent female self?” Tsukishima said, his lips forming a scandalous ‘o’.

“I DID NOT!”

“What a shame,” Tsukishima took a sip of his coffee, “And now you’re stuck here with a male version of me, how pitiful.”

“Don’t patronize me,” Kuroo said weakly, “Have you been a boy before? Aren’t you usually a girl???”

“Actually apparently I’m usually a boy, so good luck getting any from me in the future,” Tsukishima said with a smirk and a wink. 

“Wait a minute, how do you even know about all this in the first place?!” Kuroo said, pacing around and pulling at his hair.

“The last you told me about it.” Tsukishima replied calmly.

“ And you believed me?” Kuroo said skeptically.

“If I didn’t I wouldn’t be here teasing you like this,” Tsukishima said simply, lifting his cup to his mouth.

Kuroo gaped at him.

“What kind of reaction is that? How can you be so blasé about it? Wouldn’t you normally think I’m insane?”

“Well I certainly considered that, but I figured it’s such a weird thing to lie about,” Tsukishima replied nonchalantly, “Plus it’s not like I could forget how weird you get every year after your birthday.”

“You’re really weird, you know that?” Kuroo said bluntly.

“That’s rude,” Tsukishima remarked.

“How much did I tell you about me?” Kuroo asked more seriously.

“That it’s mostly the little things that change, things you don’t care about much, but sometimes there’s bigger changes,” Tsukishima fiddled with his cup, “You can sense the big changes but they’re emotionally draining. The universes have never been too different, like no breathing underwater or anything. Boring. And that you always switch on your birthday.”

“It’s not my physical body that travels, it’s just my mind, or consciousness. Or I guess you could even say my soul,” Kuroo added.

“Oh?” Tsukishima raised his eyebrows in interested, “And how did you figure that out?”

“…I tested it,” Kuroo grumbled.

“Really?” Tsukishima leaned forwards with a gleam in his eyes, “How so?”

“I dyed my hair blonde the day before going to bed,” Kuroo answered, his cheeks turning red, “Next universe, no blonde hair.”

“What’s with the blushing?” Tsukishima asked, eyeing him shrewdly, “There’s gotta be more to it that that.”

“…The previous me had the same idea,” Kuroo answered, looking away, “…I woke up with hot pink hair.”

Tsukishima burst into laughter.

Tsukishima came over to visit a lot. It was fun hanging out with him and relaxing to know that Kuroo didn’t have to hide anything from him. Tsukishima often supplied helpful information about the differences in this universe, or on occasion when he was feeling particularly cheeky, wrong information that made Kuroo look like a fool. Although in hindsight, Kuroo should have known that there was no way that that weird dance Tsukishima had showed him was a common greeting. 

It was the first time Kuroo had adjusted to being in an alternate universe so quickly. And it was all thanks to Tsukishima for believing him. Kuroo felt lucky that his former self had made such a good friend. Feeling sentimental, Kuroo reached over and ruffled Tsukishima’s hair affectionately. 

“You guys sure are as close as ever,” Bokuto remarked.

They had gone over to Bokuto and Akaashi’s apartment to hang out and get drunk, a decision mostly made by Kuroo. Tsukishima was currently leaning against Kuroo, his face red from the alcohol. 

“That’s because we’re friends~!” Kuroo declared with a sappy grin on his face. 

A weird expression came over Bokuto. He exchanged a worried glance with Akaashi. 

“What?” Kuroo asked.

“Friends?” Bokuto repeated in confusion, “But I thought you two were da-”

“KUROO CARRY ME HOME.”

Kuroo, Bokuto, and Akaashi jumped as Tsukishima suddenly stood up, swaying heavily.

“IIII’MMM DRUNK,” He declared. 

It was a feat that took all three of them to get Tsukishima’s coat and shoes on. The blond was just so damn tall. Kuroo waved goodbye as he supported Tsukishima. Tsukishima wasn’t heavy, but his long limbs made him impossible to carry and so he had to settle for awkwardly slouching over Kuroo as he walked him to his apartment.

Kuroo wondered idly what Bokuto had been about to say when Tsukishima interrupted.

“Let me tell you a secret,” Tsukishima said suddenly, leaning in close to Kuroo’s ear, “Me n’ the previous you…the truth is we weren’t just friends…”

Kuroo’ss face turned red as Tsukishima’s breath tickled his ear. His throat felt dry all of a sudden. Kei, the previous universe’s Kei, flashed through his mind again, beautiful and smiling.

“We were best friends~!” Tsukishima finished with a sly smile across his drunken face.


	2. What About Now?

**Summary for the Chapter:**

> Kuroo thinks long and hard about Tsukishima being a boy. He realizes that some other things are also long and hard.

**Notes for the Chapter:**

> i'm a piece of shit

After much struggle, mostly on Kuroo’s part, the two of them finally managed to get the door open and stumble into Tsukishima’s apartment. Tsukishima promptly began stripping, first the coat and the shoes and then, much to Kuroo’s flustered shock, his pants and shirt. 

Tsukishima stretched and Kuroo found himself staring, a strange sensation stirring in his lower gut. It was the first time he’d seen Tsukishima in such a state of undress and the sight captivated him. Tsukishima was tall and lean, his skin so white it almost glowed under the poor lighting of the front hallway. His boxer briefs were a dark blue that hugged him tightly, leaving little to the imagination. 

Kuroo felt like slapping himself in the face to make sure he wasn’t just dreaming this. He suddenly felt ashamed. Tsukishima was his friend in this universe, emphasis on friend. He wasn’t a girl, that much was obvious, so why couldn’t Kuroo tear his eyes away from his bare (and flat!) chest for one goddamn minute?! 

Tsukishima turned around to toss his coat and other stuff into the closet. Kuroo’s eyes travelled slowly over Tsukishima’s body. Long legs, tight ass, slim waist and a smooth back that was much narrower than Kuroo’s. 

I’m straight, Kuroo thought, still staring at Tsukishima. 

Tsukishima turned and Kuroo felt his heart stop at the expression on his face. Tsukishima’s lips were parted slightly and moist from that little pink tongue that peeked between them briefly before disappearing back into that wet cavern. His cheeks were flushed (from the alcohol, Kuroo numbly reminded himself) and the small amount of sweat on his forehead had caused his short bangs to curl a bit more than usual. 

“You’re staaaring…” Tsukishima’s eyes gleamed and the corners of his mouth quirked up in a mischievous delight. 

Tsukishima sauntered over to Kuroo and slid his arms around his neck. Two fingers gently tangled themselves in Kuroo’s hair. 

I’m straight, Kuroo thought, his hands coming up to rest on Tsukishima’s hips. Tsukishima’s skin was soft and pliable, giving in where Kuroo pressed his fingers.

“Was I pretty in the past universe?” Tsukishima asked, his voice low.

“…Yeah,” Kuroo replied, feeling breathless. His line of sight lowered slightly to settle on Tsukishima’s lips. Kuroo felt himself lean forwards, drawn to soft-looking pinkness.

“What about this one?”

Kuroo jerked back to reality, his mind racing with thoughts he didn’t let form. Tsukishima must have seen something in his eyes because he withdrew from Kuroo, his expression as unreadable as ever. Kuroo’s hands tingled with the loss of Tsukishima’s soft skin. Kuroo shoved them in his pockets.

“Whoa, alcohol sure is scary, huh?” Tsukishima smiled, his eyes still cold, “Thanks for taking me home, Kuroo.”

“Ah…yeah…no problem,” Kuroo said thickly. He swallowed hard.

“Night, Kuroo,” Tsukishima said genially, and Kuroo knew he was being kicked out. 

“See ya later.”

“Yeah, later…”

 

“Happy Birthday, Tetsuro,” Kei said with a sly smile.

Kuroo blinked. Ah, that was right. Kei was his girlfriend. They’d been together for almost a year now. She was tall and slender and she straightened her long blonde hair to get ride of the natural curl. Kuroo’s eyes felt misty. He wondered why.

“Haha thanks…” Kuroo replied with a forced smile.

“Wow that was a lackluster response,” She raised an eyebrow, “What’s up with you?”

“Sorry, sorry!” Kuroo raised his hands, “It’s just been a rough morning!”

“So rough that you can’t talk to your girlfriend about it?” She pouted.

Her petulant expression was one that Kuroo was extremely familiar with. Secretly, he’d always thought it was cute. Usually it filled him with a light feeling of happiness, but for some reason he felt off, he felt…guilty.

“Kei, when did we first meet?” He asked.

“High school,” She replied, “We were in different grades and went to different schools, but I was the volleyball club’s manager and we met during the training week. Tanaka-san and Nishinoya-san had a fit when we started dating.”

Right, Kuroo should have known the answer would be something like that. He looked down at his clenched hands. He never told Kei about the alternate universe thing. He never told anybody before. 

“Or should I say we met last year when we took the same class?” Kei said, her voice low.

Kuroo looked up in surprise. Kei felt different. 

“Did you think I didn’t notice?” She asked, her voice was playful but her eyes were dark.

No, Kei always noticed. 

Kei’s hands were holding his shirt tightly and she looked at him evenly.

“Do you love me?” She asked quietly.

“Yes,” Kuroo breathed.

“Even now?” Tsukishima looked at him, unmistakably male hands still intertwined in his shirt, still looking at him with that even gaze. 

Oh shit, Kuroo thought as he leaned forwards. Dammit, Kuroo thought as he met the softness of Tsukishima’s lips. Fuck, Kuroo thought as their tongues intertwined greedily.

 

Kuroo woke up the next day with a headache. He flung an arm over his eyes. He remembered last night’s events with an acuteness that hardly seemed fair considering the alcohol involved. Not to mention that dream; that was definitely against the rules. He could still feel the softness of Tsukishima’s skin, the heat of him pressed against him, and the tickle of the slender fingers playing with his hair. The imagined feel of his lips…

It was the alcohol, Kuroo reminded himself miserably. 

He sat up and realized with horror that his boxer briefs were sticky. He pulled the covers back and looked down. With a resigned sigh, he dragged himself out of bed and peeled off his underwear, tossing it into the hamper on his way to the bathroom. His bedhead was worse than usual and his eyes were bloodshot. He showered quickly, wishing the guilt would wash away as nicely as the evidence did. He wondered if he’d really screwed things up, if Tsukishima would even come near him anymore. He stepped out of the shower and wrapped a towel around his waist. 

It was his fault, Kuroo thought as he brushed his teeth. Tsukishima was the one who had gotten too drunk. Tsukishima was the one who took off his clothes in front of him. You were the one who was attracted by it, a sly voice whispered in Kuroo’s mind. Kuroo spat. 

There was a ringing coming from his bedroom. Kuroo stood and wondered what it was before realizing with panic that it was probably his cell. He rushed in and snatched it up, pressing the answer button just in time. 

“Tsukishima!?” Kuroo nearly yelled.

“Ouch, man! No need to shout!” Bokuto chastised him from the other end of the line.

“Oh, it’s you,” Kuroo said glumly.

“Wow, rude,” Bokuto said, “And here I was, being a good friend and figuring I’d call you up and see how you’re doing since you’re probably devastated after getting dumped by Tsukishima. Life’s harsh man, trust me, me n’ Akaashi didn’t see it coming either!”

“Wha-? Wait a minute, what are you talking about?” Kuroo rubbed his temples with his right hand, “What do you mean Tsukishima dumped me?”

“He didn’t?” Now Bokuto sounded confused, “But I mean, he called us this morning to say you two weren’t together anymore, which was a real shock! And I know how much you like him, I mean it’s practically impossible to get you to shut up about him normally, and you did seem a little strange yesterday and-”

Bokuto’s words faded into the background as Kuroo absorbed the new information. Suddenly a lot of things made sense, the way Tsukishima seemed to know everything about him, and the small looks he sometimes snuck towards Kuroo when he thought he wasn’t paying attention. Kuroo felt like punching himself for being so stupid. He'd stupidly assumed that since Kei was a guy in this universe that they couldn't possibly have the same relationship that they did in the last, but obviously that wasn't the case. Kuroo thought aboutt last night's dream and the resulting mess he had woken up to. Yeah, Kei being a guy was probably much less of a problem than he'd assumed it'd be.

“Bokuto, I need to see Tsuki-,” Kuroo took a deep breath, “I need to see Kei, can you tell me where he is?”

**Notes for the Chapter:**

> i wanted to make it a bit more explicit but i just didnt work out. it will next chapter though.


	3. Found You

**Summary for the Chapter:**

> It's a happy ending! (kinda)

**Notes for the Chapter:**

> They do the do
> 
> Tsukishima is really out of character...

Kuroo sprinted down the sidewalk. Bokuto’s encouraging shout of, “Go get ‘em tiger! Woohoo!” was still ringing in his ears. He still didn’t quite know what he wanted or what he was feeling but he knew that he had to see Tsukishima, he had to see Kei or he’d regret it for the rest of his life. 

I must be an idiot, Kuroo thought to himself, wasn’t I the one who swore never to get into a relationship with someone? But then Kei…Tsukishima…she, no he, or I guess they…? Kuroo shook his head. It didn’t matter; Kei was Kei, Kuroo realized. 

And Kei was beautiful. Kei was petulant and pessimistic and sardonic and stubborn and Kei was so unbearably cute that Kuroo didn’t know what to do with himself. 

Kuroo rounded the corner and promptly ran into someone. The world tipped over and pain shot up his knees as he fell on top of someone. 

“Ow! What the hell?” 

He knew that irritated voice! Kuroo’s head jerked up. Kei was glaring up at him, his spilled coffee lying a short distance away in the grass. Kei’s eyes widened as he recognized Kuroo and his mouth fell open in surprise. 

Kuroo found himself unable to tear his eyes away from Kei. He noticed small things about him; things like how pretty it was when the sun shone through the fine strands of his hair, the way his face turned a soft pink when he noticed Kuroo staring, and the tinge of redness around his eyes. Kuroo wondered if the last one was his fault and mentally kicked himself for it. Kuroo also found himself wanting to touch him as he noticed these things. It was perplexing and irritating and it was beyond Kuroo’s control. 

Why did he let himself waste so much time? 

“You are,” Kuroo said breathlessly.

“Huh?” Tsukishima said irritably.

“Pretty,” Kuroo replied, “You’re pretty in this universe too. No, actually you’re beautiful.”

For the first time in this universe, Kuroo had rendered Kei speechless. It was a pretty good feeling, Kuroo decided with a grin. 

“Can I kiss you, Kei?” Kuroo said in a quiet voice, his eyelids lowering as he slowly leaned in.

“We’re in public, idiot!” Kei mumbled.

“Then shall we move somewhere more private?” Kuroo asked with a grin.

He reluctantly got off of Kei and offered him and hand. Kei swatted it away before getting up himself and brushing off his clothes with a huff. Kei started walking, ignoring the happy look on Kuroo’s face.   
“You better replace my coffee,” Kei said without turning around. His voice was as cool as ever, but Kuroo could see the red tips of his ears.

“Of course!” Kuroo said, slyly wrapping an arm around Kei’s waist. Kei stiffened, but didn’t brush him away. 

“If’s not going to be easy being with me,” Kei mumbled.

“It wouldn’t be easy even if I didn’t switch universes every year,” Kuroo remarked, pulling Kei closer, “You’re one stubborn cookie.”

“I hate you…” Kei turned away with an annoyed and embarrassed expression.

“But that’s what makes you so cute!” Kuroo pecked him on the cheek. 

“Geh!” 

Kuroo rubbed the spot on his side where Kei had elbowed him. Kei walked ahead of him and for a moment Kuroo paused. Was this fair of him? To continue this relationship when he knew it would end in less than a year? A jolt of fear flashed through him. 

Kuroo clenched his hands. No, he wouldn’t let that happen. Whatever universe he was in, he would find Kei, and he wouldn’t let him go. Kuroo took a step forwards and then another, faster and faster until he caught up to Kei’s side.

This time when they entered Kei’s apartment Kuroo was the one who started removing Kei’s clothes, sliding them over his pale skin and letting them fall to the floor. 

Kuroo peppered kisses down Kei’s neck, sucking lightly as Kei tried not to moan. Kuroo nipped Kei’s collarbone and Kei let out an involuntarily gasp.

“I hate you…” Kei said in a small voice, his blush spreading down his neck. 

“You hate me enough to seduce me while we were drunk?” Kuroo murmured in his ear. 

“You were the one staring,” Kei argued.

Kuroo grabbed Kei’s hips and grinded into them. Kei moaned deliciously and Kuroo did it again, harder this time.

“How could I not?” He panted, “Fuck, Kei, where’s your bedroom?”

“Down the hall, first door on the left,” Kei gasped out.  
Kuroo slid his hands behind Kei’s thighs, but Kei scrambled out of his arms before he could lift him.

“Idiot! You’ll bash my head into the ceiling!” Kei grabbed Kuroo’s hand in a huff and led him down the hall.

“Didn’t think about that,” Kuroo laughed, “Has that happened before?”

The red flush across Kei’s face answered that question. 

They resumed making out once inside Kei’s bedroom. Kuroo kicked the door closed behind them out of habit and then focused on pushing Kei towards the bed. Kei fell backwards onto it and Kuroo grinned down at him. 

“Wait,” Kei reached up and slid his hands under Kuroo’s black t-shirt.

“You’re still clothed,” He pouted.

“Wanna help me with that?” Kuroo said slyly.

Kei yanked his shirt up roughly, almost strangling Kuroo in the process. 

“Are you going to finish what you started or am I going to have to kill you for being an idiot?” Kei said irritably.

“Okay, okay!” Kuroo laughed, “I get it, I’ll stop messing around.”

Kuroo stood up and threw his shirt aside. He smirked down at Kei as he reached for his belt. Kei had stripped so nicely for him last night, it was only fair for Kuroo to return the favor. Kei ‘s golden eyes travelled over Kuroo’s hard stomach, his defined biceps and then finally to the bulge pressing against the front of his jeans. Kuroo’s face was flushed with lust and his eyelids lowered as he undid the belt and slid out of his jeans and underwear with a grin. 

He placed a knee on the end of Kei’s bed between Kei’s legs and leaned forwards. 

“You look good like that,” He said, taking a moment to appreciate Kei’s body laid out beneath him. Kei was so pale against the dark grey sheets. Kuroo leaned down and sucked on his collarbone, leaving behind a red mark. That looked even better. 

He teased Kei with soft kisses that travelled to his left nipple. Kuroo let his lips ghost over the puckered nub before opening his mouth and holding it gently between his teeth. Kei let out a small whine as Kuroo bit down lightly. His fingers traced lines up and down Kei’s sensitive sides and then dug in to his waist as Kuroo trailed his tongue across Kei’s chest to the other nipple. 

One hand snuck down to the front of Kei’s boxer-briefs and fingers skirted around the top of his underwear. Kuroo let out a low chuckle at Kei’s hiss of frustration as he teased him. 

Kuroo finally moved his head lower, trailing kisses and sucking at Kei’s skin as he went. He mouthed over the bulge in Kei’s underwear (red this time) and ran his hands down Kei’s thighs. Kei gasped when Kuroo dug his fingers into the soft flesh and his tongue licked a wide strip up Kei’s cock. The tip of his cock was peeking out the top of his underwear and a pearly dribble of pre-cum had leaked onto his stomach. 

Kuroo snaked his tongue around the head of Kei’s cock. Turning his head slightly, Kuroo lifted the fabric of Kei’s underwear with his tongue and took it between his teeth. He dragged down Kei’s underwear with his teeth, fingers kneading the back of Kei’s knees as he did so. 

Kei shivered as cold air meet the sensitive skin of his cock and then moaned as the heat of Kuroo’s tongue covered it. Kuroo had never sucked a dick before, or at least not this version of himself, and while it wasn’t exactly pleasant, it wasn’t bad either and the noises Kei was making because of it was more than enough reason for Kuroo do his best. 

He licked a few languid strips up and down Kei’s cock before sliding his lips around the head and swirling his tongue over the top. He hollowed his cheeks and took more of Kei into his mouth, rubbing his tongue against the underside of Kei’s cock as he sucked. Kuroo could hear Kei moaning above him and it sounded absolutely sinful. Kuroo bobbed up and down on Kei’s cock, quickening the pace as he got used to it.

Kei’s hand was in Kuroo’s hair and the feel of it gently pressing down on the back of his head was driving Kuroo crazy. Kuroo’s own cock was feeling unbearably hot and he was almost desperate enough to rut into the mattress. Kuroo moaned around Kei’s cock and Kei’s hand clenched around his hair. Kuroo’s hands moved from the undersides of Kei’s legs to cup his firm ass. He massaged his fingers into the yielding flesh and moaned around Kei again, wanting to feel Kei pull at his hair.

“Ngh…Kuroo…” Kei panted, “M’gonna cum…”

Kei was pulling at his hair, trying to get him to lift his head but Kuroo took him deeper and faster. Kei’s cock bumped the back of Kuroo’s throat but Kuroo took in in stride with a small grunt. Kei released with an involuntary jerk of his hips and a loud moan. 

Kuroo managed to catch most of it in his mouth, but a few white strands hung between his lips and Kei’s cock. Kuroo leaned back on his knees and lifted his hand to his mouth. Kei could see Kuroo’s tongue peeking out of his open mouth. His eyes widened as he saw his cum dribble down Kuroo’s tongue and pool into his palm. He grinned cheekily at Kei as he licked the lingering strands off his lips. 

“What are you…?” Kei gasped as a cum-slicked finger pressed against his entrance.

“You gave me so much,” Kuroo practically purred, “Why let it go to waste?”

Kei’s breath hitched as Kuroo’s finger slipped past the tight ring of muscle. Kuroo wiggled it around, watching Kei’s face carefully for signs of pain and discomfort. 

“You’re doing so good,” Kuroo said, kissing Kei’s forehead, “Just a little more and I’ll make you feel wonderful, I promise.”

“Have you done this before or something?” Kei asked through deep breaths.

“I’m guessing I’ve done it before with you,” Kuroo winked.

“That doesn’t count and you kno- ah!” Kei threw his head back and his back arched.

Kuroo froze.

“Did that hurt?” Kuroo asked worriedly. 

“No, idiot! Do that again!” Kei ordered, his face turning even redder.

Oh. Ohohoho…Kuroo felt a shit-eating grin spread across his face. He felt around with his finger and pressed down where he thought he had earlier. Kei cried out again, his back arching and his toes curling. 

He slipped in a second finger easily and scissored them, making sure to brush against that spot every so often. Kei was so soft inside and Kuroo was soon able to slip in a third finger.

“Hurry up,” Kei gasped, “I want you…”

“Condom?” Kuroo asked.

“In the drawer beside my bed,” Kei answered impatiently.

Kuroo quickly fetched a condom and ripped it open with his teeth. He rolled it over himself and then slicked it up with the remainder of Kei’s cum. Kuroo felt his cock twitch at the sight of Kei’s lust-filled eyes looking at him hungrily from the bed.

Kuroo lifted one of Kei’s legs over his shoulder and lined up against Kei’s entrance. He pressed against the small opening and let out a deep groan as the head of his cock slid inside.   
It was hot, so hot and it took all of Kuroo’s willpower not to thrust inside immediately. He slid in slowly, moving back and forth in tiny increments as Kei got used to it. Kuroo muttered a shaky “fuck” as he finally slid all the way inside. Kei was so tight, tighter than Kuroo had ever felt before.

“…You can move…” Came Kei’s breathy voice from above Kuroo. 

“Fuck, Kei this feels way too good,” Kuroo’s hips jolted forwards.

He dragged out slowly and then thrust back in, gasping slightly at the delicious friction. He tried to angle for that sweet spot inside of Kei and knew he found it when Kei cried out in pleasure. He set up an even pace. One hand held onto Kei’s leg on his shoulder and the other firmly gripped Kei’s hips, his thumb digging into the small dip on the inside of his hipbone. 

“Harder…Kuroo,” Kei begged, the corners of his eyes teary.

Kei didn’t have to ask twice. Kuroo’s hips picked up speed, hitting Kei’s prostate with every thrust. 

“Call my name,” Kuroo said breathlessly, “Please Kei, call me Tetsuro.”

“Tetsuro…” Kei called out in a sweet voice. 

Oh fuck, Kuroo dived forwards to capture Kei’s lips. He wasn’t going to last at this rate. Kuroo let Kei’s leg slip off his shoulder and moved his hand to grasp Kei’s cock. He stroked in time to his thrusts. 

“I’m gonna cum, Tetsuro,” Kei said, his arms wrapping around Kuroo’s neck.

“Me too,” Kuroo said into Kei’s chest. 

Their pace became frantic as they neared release. Kuroo came first and thrust so deep into Kei that his balls rammed against Kei’s soft ass. Kei came soon after and Kuroo’s hand pumped him as the sticky white strands shot up his stomach. Kuroo collapsed onto Kei and wrapped himself around him, ignoring the mess on Kei’s stomach. 

“I love you, Kei,” Kuroo nuzzled into Kei’s neck, “All of me does.”

“How do you know that?” Kei muttered.

“Admittedly, I’ve only met you in another universe once and you were a girl there,” Kuroo said, lifting his head, “But I was completely in love with you there and I’m completely in love with you here.”

Kuroo interrupted himself to kiss Kei on the lips.

“Important things don’t change universe to universe, things like needing to breathe air or drink water,” Kuroo said softly, “Loving you is as important to me as needing to breathe air, Kei.”

“God, where you do get these lines?” Kei covered his face with his hands.

“I’m sorry, Kei, I’m probably going to make you cry a lot of times in the future,” Kuroo and smiled sadly. He stroked Kei’s cheek, “But I promise to make up for it. Even if it’s a different me, it’s still me. I’m pretty stubborn when I decide things, you know.”

“You know, I used to be the kind of person who thought that as long as I never had anything important to me, I could never be hurt,” Kei said from behind his hands, “Then you showed up out of nowhere like an idiot and made me fall in love with you. So it’s all your fault that I now have something I can’t bear to lose.” 

“I can say the same of you,” Kuroo said, kissing Kei’s hands, “I always thought that I couldn’t love anyone or have serious lovers; not with the way I am. I thought I’d just end up leaving them and they’d think I’ve forgotten them.”

Kuroo gently pried Kei’s hands away from his face.

“But after meeting you, this you, I’ve realized that it doesn’t have to be that way. Our experiences and some of our memories might be different, but we’re still the same people. These feelings,” Kuroo lifted one of Kei’s hands and held it to his chest. Kuroo’s chest was hot and Kei could feel his heart beating quickly under the warm skin.

“These feelings transcend this universe,” Kuroo grinned, “Aren’t we proof of that?”

“Have you ever woken up in the same universe before?” Kei asked him.

“Lightening never strikes the same place twice,” Kuroo answered.

“Find me again, Kuroo,” Kei said, pressing a hand to Kuroo’s cheek, “Promise me you will.”

“I promise,” Kuroo placed his hand over Kei’s, “I can’t imagine ever living without you.”

Kuroo leaned down to kiss Kei again. This kiss was sweet, just a gentle press of lips against lips. 

“I swear I’ll find you again and again, for the rest of our lives,” Kuroo said against Kei’s mouth. 

“I love you, Kuroo,” Kei said in return.

“Come on, call me Tetsuro!” Kuroo said, pulling back to smirk at him, “You didn’t seem to have a problem with it when my cock was-!”

“Sh-shut up!” Kei sputtered in embarrassment, “Shut up! Shut up! Idiot!”

 

Kuroo woke up alone. For a short, panicked moment he wondered where Kei went. Then he remembered Kei wiggling out from under him in an annoyed huff to take a shower. There was a note on the bedside table from Kei, saying that he went to get another coffee. The apartment was quiet when Kuroo walked out of Kei’s bedroom. Kuroo helped himself to Kei’s shower, washing off the evidence of their earlier activities down the drain. 

He heard the door as he was drying off and he felt a jolt of excitement. What am I, Kuroo thought to himself, a puppy? He wrapped the towel around his waist and left the bathroom to find Kei. 

Kei was in the kitchen, quietly putting away dishes that had been in a drying rack. Kei’s hair shone pale gold in the light coming through the window and the back of his neck was slightly pink from the cold. Kei was humming under his breath and there was a soft, happy look on his face. 

What did Kuroo even do before he realized how fun it was to look at Kei?

Kei finally saw Kuroo leaning against the doorframe and he made a small noise in his throat in surprise. A pink flush spread across his cheeks at having been caught humming. 

Kuroo walked over to him and hooked a finger through Kei’s belt loop. 

“Found you,” He said happily, pulling Kei in for a kiss.

**Notes for the Chapter:**

> This was really hard to write because I actually get so embarrassed writing this kind of stuff. I think I'm going to add an epilogue/prologue but for now, it's finished.

**Author's Note:**

> they were totally dating before, poor Tsukishima


End file.
